1. Field of the Invention
The present invention relates generally to an improved method of designing and manufacturing a probe card assembly and more specifically to use of prefabricated elements to speed design and manufacture of the probe card assembly.
2. General Background and Related Art
FIG. 1 illustrates a simplified overview of a typical flow of common activities involved in designing and manufacturing a semiconductor device, such as a microelectronic “chip.” Initially, the semiconductor device is designed 10, and a tester and testing algorithms are selected and/or designed 12 for testing the semiconductor device. Using data regarding the semiconductor device design, the tester, and/or the test algorithms, a probe card for testing the semiconductor device is then custom designed 14. Usually concurrently, preparations are made to begin manufacturing the semiconductor device in commercial quantities 16. Once the probe card is designed and manufactured and preparations to manufacture the semiconductor device are completed, semiconductor devices are manufactured in commercial quantities 18. As the semiconductor devices are manufactured, each is tested 20, and good semiconductor devices are shipped to customers 22.
FIG. 2 illustrates a simplified block diagram of a typical test arrangement for testing the semiconductor device at step 20. A tester 120 generates test signals to be input into a semiconductor device under test 160. The tester 120 then monitors response signals generated by the semiconductor device under test 160. The tester 120 communicates with the semiconductor device under test 160 via a probe card assembly 100.
As shown in FIG. 2 and FIG. 3 (which illustrates a cross-section of the probe card assembly 100), a typical probe card assembly 100 includes a printed circuit board 102, which usually includes a number of tester contacts 130 for connecting to the semiconductor tester 120 (not shown in FIG. 3) via connections 122 (not shown in FIG. 3). A probe head 106 is attached to the printed circuit board 102. The probe head 106 includes probes 108 for contacting test points 162 on the semiconductor devices being tested 160.
As shown in FIG. 3, electrical traces 150 on or within the printed circuit board 102 connect the tester contacts 130 to the probe head assembly 106 and ultimately to probes 108. Thus, electrical paths between inputs and outputs (not shown) on the semiconductor tester 120, on one hand, and the probes 108, on the other hand, are established. As also shown in FIG. 3, the probe head 106 is typically connected to the printed circuit board 102 via connections 152, which may be, for example, solder ball connections or contact pins soldered to the printed circuit board 102, the probe head 156, or both. Traces 150 on or within the printed circuit board 102 connect the tester contacts 130 to the connections 152, and traces 154 on or within the probe head 106 connect the connections 152 to the probes 108.
Thus, in essence, the probe card assembly 100 acts as an interface, providing numerous electrical paths for test and response signals between the tester 120 and the device under test 160. As is known, a probe card assembly 100 must be custom designed to meet the specific test needs of the device under test 160 and the test specifications of the tester 120. For example, the probes 108 of the probe card assembly 100 must be custom positioned to match the pattern of test contacts 162 on the device under test 160, and the probe card assembly 100 must be custom designed such that each probe 108 is electrically connected through tester contacts 130 to the proper tester connection 122. For this reason, as shown in FIG. 1, the design and manufacture of the probe card assembly 14 does not begin until the semiconductor device has been designed 10 and a tester and/or testing algorithms selected 12.
As is known, semiconductor devices cannot be shipped to customers 22 until they are tested 20, and the probe card assembly is a necessary element of the test system. Thus, even if the step of preparing to manufacture the semiconductor devices 16 has been completed, manufacture, testing, and shipping of the semiconductor devices 18, 20, 22 cannot proceed until design and manufacture of the probe card 14 has been completed. Thus, if the design and manufacture of the probe card 14 takes longer than the preparations to manufacture the semiconductor devices 16, which is increasingly the case, the extra time taken in designing and manufacturing the probe card lengthens the entire process shown in FIG. 1 and delays the final step of shipping semiconductor devices to customers 22. Thus, a way of shortening the step of designing and manufacturing a probe card assembly is needed.